3(16) administrator signing 5500 for client question

One of the selling points of a 3(16) service is that they sign the 5500 for their clients.

I understand that a true 3(16) administrator can sign as Plan Administrator on 5500's.

But I always thought that if the Plan Administrator and Plan Sponsor were the same, you only needed a signature on the top line, Plan Administrator, but if they were different, you need 2 signatures.

So, obviously the appointed 3(16) is NOT the sponsor.

Wouldn't two signatures still be necessary?

If not, why are there two lines?  If you only sign as sponsor w/o administrator the filing fails.

Form 5500 is used for at least two (and sometimes three or four) reporting or disclosure requirements.

One of those is Internal Revenue Code § 6058(a)’s command for an information return:

Every employer who maintains a pension, annuity, stock bonus, profit-sharing, or other funded plan of deferred compensation described in part I of subchapter D of chapter 1, or the plan administrator (within the meaning of section 414(g)) of the plan, shall file an annual return stating such information as the Secretary may by regulations prescribe with respect to the qualification, financial conditions, and operations of the plan; except that, in the discretion of the Secretary, the employer may be relieved from stating in its return any information which is reported in other returns.  https://irc.bloombergtax.com/public/uscode/doc/irc/section_6058

One might read that long sentence, including its “or” phrase, to treat an employer’s duty as met if the plan’s administrator filed a return that meets the requirement.

If a plan is not ERISA-governed and has no other need for an administrator to adopt the IRC § 6058 information return, the return might be filed only by an employer, with no signature for an administrator.

Let’s not try to defend or explain the agencies’ design of the form and instructions; it’s not what we would have done.

Then why are there two lines if only one is needed?

It seems the administrator MUST sign the form.  The Sponsor is optional then?

If the Administrator and Sponsor are different people, do they both have to sign?

What if they are different people and ONLY the Sponsor wants to file?

The edit checks in the EFAST system will reject a filing if only the Sponsor signature is present.